1. Field of the Invention
The present invention relates to continuous assemblies of postal correspondence units with incorporated detachable documents.
2. Description of the Prior Art
In order to facilitate the processing of office forms for mass correspondence, there exist in commerce various types of continuous assemblies designed to pass through a suitable office printing machine, for example, the print-out device of a computer. These assemblies are delivered to the user folded accordion-style along transverse lines of weakness, each panel of the accordion element constituting a postal correspondence unit, sealed in manufacture or sealable after folding. After passage through the print-out device, the "separation into units" of the assembly is carried out by separating the panels from one another in a breaker or in a cutting device. Mostly, the assembly is provided with marginal perforations serving for driving it through the processing machines and the perforated margins are detached either by continuous cutting in the breaker or the transverse cutting device or by the addressee by means of the longitudinal detachable perforations.
Of course, the assembly can receive in the course of manufacture, over the whole or part of the surface of one or several of the elements which constitute it, printing of a general nature (business letter-head of the sender, indication of the time for reply, list of products of services placed at the disposal of the addressee, method of settlement, form to be filled, etc..) as well as various markings (trade mark, signs, patterns for decoration or to prevent reading by transparence of the closed folder), this printing and marking then being repeated on each panel and only the personalised printing, relating to a given addressee being done on the office printing machine.
When each unit of correspondence is sealed in manufacture, the assembly is in the form of a bundle of superposed and continuous paper strips on which the particular information printed by the office printer is selectively reproduced by known means (carbon areas, reactive papers, self-reproducing paper, etc.). Such articles are commonly denoted by the English term "mailers". Separately from a first possible strip, called the recording or checking strip, which receives all the information printed by the office printer, the top strip forms the upper wall of the envelopes of the successive folders and the lower strip the back wall of said envelopes which are sealed by two longitudinal glueing lines which follow the detachable lateral margins of the assembly and transverse glueing lines framing each of the lines of weakness provided by folding in accordion fashion. All the intermediate strips are intended to form the internal documents which can include an envelope called a return envelope and for this they are suitably cut out so as not to be "stuck" at least by the transverse adhesive. Lines of detachable perforations or of breakage starting are formed on certain strips or on all of the strips so as to permit for each unit folder, its opening and the seizing of the incorporated documents by tearing away of at least one transverse or lateral strip or, automatically, by a sudden pull applied at a certain point. Mostly the intermediate strips are assembled together and with the top and bottom strips by one only of their longitudinal edges, that is to say each inside document has three free edges and one detachble lateral edge.
These "mailers" have a certain number of drawbacks. Firstly, the assembly into a bundle of the different strips requires a machine of very specialized formation, large and of high cost which, supplied by as many spools as there are strips, provides for the cutting-out of the intermediate strips, the glueing, the lateral assembly strips and the formation of folders for the accordion folding. Moreover, when the intermediate strips are held by one only of their lateral edges, the latter presents with respect to the other, an excess thickness which interferes with the formation of a "bundle" of the accordion folding and limits the possible number of inside documents which, besides, cannot have notable differences as to their dimensions as for that corresponding to the transverse direction of the strips. Lastly, the folders being sealed in manufacture, none of the inside documents can receive a direct impression from the printer, which prevents their passage through optical or magnetic readout machines.
There have been proposed, continuous assemblies of mailers not sealed in manufacture, of the letter-card type. In these assemblies each panel of the accordion elements includes at least three flaps which can each receive a direct impression. According to the number of flaps and the method of folding provided for the letter-card (folding accordion-style or rolled folding) the address of the addressee is borne directly on the flap forming the face of the sealed folder or appears through a window formed on said face flap after having been struck on another. After passage through the printer the various panels are separated as has been stated above and each correspondence unit is folded along weakness lines separating the different flaps, preferably in a suitable folding machine, and sealed automatically by simple pressure due to lines of self-adhesive areas or by pressure and heating by means of thermo-adhesive stripes. On reception, the addressee opens these folders by detaching narrow strips, by means of the lines of detachable perforations, on three sides or at least on two opposite sides and unsticking the third when it involves self-adhesive areas.
These letter-cards have however certain drawbacks. The principal drawback resides in the limitation of the number of flaps. It is difficult to exceed three flaps whilst remaining within reasonable limits as to the length of the panels of accordion folding of the continuous assembly. If all the flaps can receive a direct impression, contrary to the internal documents of a "mailer", it is not possible to obtain on an end flap detachable by the user, a lower free edge for optical read-out (reply-card, universal payment voucher) except if the separation into units is effected by cutting (guillotine or rotary knife) and not by a breaker. Lastly, if the detachable flap has to include two free edges (lower edge and right-hand edge) to pass into a magnetic read-out machine (cheque for example) it is necessary for the corresponding flap to be cut laterally on the right-hand side, during manufacture, which involves interruptions in the right-hand lateral driving margin and the possibilities of mishaps.
In all cases the internal documents are derived from the single continuous strip (letter-cards) or are obtained by flat cutting-out of intermediate strips paid out from spools ("mailers"). It is impossible to incorporate in the correspondence units of these continuous assemblies, documents arising from other sources of mechanical or manual formation, such as a large cross-folded printed form, a plastic card, a fascicle or a catalogue, etc...
Finally, it is known, besides, to attach by glueing to a simple continuous strip provided with marginal perforations or any other drive means, single leaves, wads of leaves, pockets, etc., so as to enable such elements to pass through an automatic printer. The continuous strip is then called a support strip or pilot strip. The forming machines enabling this to be carried out are simple machines, relatively inexpensive and which, until now, can effect this positioning of the attached elements in extremely accurate manner.